1. Technical Field
The present disclosure generally relates to a fray tester for sutures. In particular, the disclosure relates to a test apparatus and related methods for evaluating surface durability in terms of fray resistance or breakdown performance of a suture when rubbing against itself or against a solid surface material.
2. Background of the Related Art
Sutures are often used in surgical procedures for holding cut tissue surfaces in apposition for a period of time sufficient for healing. Non-absorbable sutures, e.g. sutures made from non-bioabsorbable materials such as polyolefins, nylon, cotton and the like, are generally removed after a period of time or may remain as long term implants. Absorbable sutures, e.g. those fabricated from bioabsorbable materials such as polymers of lactide and glycolide, collagen, and the like, are gradually degraded and absorbed by the body, and do not require subsequent removal.
A suture having a good degree of flexibility and pliability can conform closely to body tissue without undue pressure. Good flexibility and pliability enhance the degree to which a suture can be tied down, knotted and securely placed in a desired position. Various attempts have been made to modify and optimize the physical characteristics of gut sutures. For example, various suture coatings and tubing fluids have been developed to achieve or enhance flexibility and pliability, and also to improve the handling characteristics of sutures, such as fray resistance or run-down performance.
In addition to the research efforts on suture materials, coatings and tubing fluids, several testing techniques have been adopted for evaluating such handling characteristics of sutures.
An example of a fray resistance test is described in U.S. Pat. No. 5,584,858. Such fray tester utilizes a static suture wound around rollers, and a dynamic suture wrapped twice at a point around the static suture with a weight attached at one end of the dynamic suture, the dynamic suture being subject to rubbing cycle against the static suture until the sutures break to stop the test.